This report presents the case of a 23-year-old female patient who presented with the symptoms of worsening lower back pain along with decreased perineal sensation and urinary incontinence. Split cord syndrome, also called diastematomyelia, is a rare congenital disorder that is more common in females. The exact logic for this gender preference is not understood, however, this association emphasizes the consideration of sex-specific factors in congenital malformations [8]. Generally speaking, diastematomyelia is found during childhood or as an incidental discovery during adulthood. Rarely, it can present with symptoms of its own as well just as it did with our case [9].
Its embryogenesis is not completely understood, however, it is proposed that it occurs due to an anomaly in the neurenteric canal (canal of Kovalevsky). The neurentetic canal runs from the yolk sac to the amniotic cavity through the notochord [10]. The most notable symptom of the clinical presentation of diastematomyelia are the cutaneous manifestations such as a hairy patch on the back, and a dimple or a tuft of hair. This is usually followed by the loss of neurological function or weakness and pain [11]. Scoliosis is also an associated symptom. Our patient also had progressively increasing lower back pain along with progressive loss of neurological functions. Progressive lower back pain is perhaps the most common symptom of diastematomyelia [12, 13]. The loss of neurological function such as continence and paresthesias in the area of distribution occurs quite frequently and was also reported by Vissarionov et al in their cohort [13]. The neurological symptoms can include sensory and motor symptoms. Sometimes, the condition presents with symptoms after the occurrence of a trauma but that was not the case with our patient. The degree of pressure produced by the bony or fibrous spur directly correlates with the severity of clinical symptoms [6].
There are two types of diastematomyelia. Our patient presented with Type 1, in which both the cords have their separate dural pouches. Type 1 is associated with a relatively more severe clinical presentation. It also has vertebral abnormalities in association with hydromyelia, whereas type 2 only has hydromyelia [14]. If diastematomyelia is suspected in a patient, then radiological investigations are ordered. They are ordered to find the characteristic finding of a widened interpedicular distance of the vertebrae at the level of the split cord. MRI is usually the first investigation ordered owing to its good specificity and sensitivity which was the case in our report as well. It can also be diagnosed in the fetal scans in the third trimester [15]. However, a better view of bony alterations is viewed by a CT scan and thus occasionally, both investigations are carried out simultaneously [16].
The treatment modalities of diastematomyelia are dependent on the severity of the clinical presentation. In asymptomatic or mildly symptomatic cases, no intervention is performed and only observation via regular follow-ups is done [17]. However, in moderately symptomatic cases, conservative treatment can be done with the administration of either muscle relaxants (such as baclofen or tizanidine) or pain-managing drugs (such as NSAIDs). This conservative treatment is a good alternative to surgical options and involves minimal risk, however, it should also be supplemented by physiotherapy and it provides a temporary effect in most cases [18]. In cases where severe symptoms are present, or conservative treatment has failed, surgery can be performed. Even though surgery provides a definitive treatment for the condition, its role is still controversial [19]. The usual course of the surgery involves decompressing the spinal cord, followed by the removal of the bony spur or the fibrous septum, and then repairing and reconstructing the dural sacs. Laminoplasty is preferred over laminectomy in such surgeries [20]. Pavlova et al performed such surgeries on 27 cases and reported favorable outcomes [21].